# Posts by AMY

Total # Posts: 4,232

**physics HELP!! **

A diffraction grating has 600 lines/mm. Light with a wavelenght of 600nm is incident on it. A screen is placed 0.1m from the grating. Calculate the distance from the 1st and 2nd order maxima on the screen

**physics HELP!! **

A capacitor is constructed from two aluminium plates 1.5cm on a side separated by 0.2mm of air. (A) Calculate the capacitance of the capacitor. (2 sig figures) (B)Calculate the voltage required to store 1nJ of energy in the capacitor.

**Math**

6 times the difference of a number and 9 is 18 less than the number. I need to write out as an equasion. Help!

**physics (mirrors)**

An object is placed from a concave mirror with a radius of curvature of 50cm. The object has a height of 5cm. a)Calculate the focal lenght of the mirror. b)Calculate the position of the image formed by the mirror. Is the image real or virtual? c)Calculate the size of the image...

**physics **

1. a) using heat exchange and conservation of thermal energy determine the specific latent heat of fusion for ice. b) determine the percentage error The data we determined was: Hot water: mass - 0.1kg initial temp-87C final temp - 56 C Melted ice: mass - 0.024 kg Initial temp...

**Physics **

Determine the percentage error. So we found that aluminium has a specific heat capacity of 18441J/KgC And I know that the percentage error = mv-av/av x 100% But how do we know the actual value of aluminium? My teacher never gave it to us. And when it says mv-av does it mean ...

**Physics**

Thank you for answering! So when I did the math I got 18,441 j/kg degree c However the actual value is supposed to be 900.did I do the math wrong or did I just do something wrong in the experiment? Thanks!

**Physics **

Using heat exchange and conservation of thermal energy, determine the specific heat capacity for your metal. So the data we have is: Aluminium: Mass - 0.004 Initial temp - 100C Final temp: 32C Water: Mass -0.1 Initial temp - 20C Final temp - 32C I know that the formula is mct...

**chemistry **

So we did an experiment where we mixed Cacl2 and NaCl and then found the mass of the precipitate. Then we compared it to reference data on a standard curve to see the mass of Na2Co3 reacting to produce the CaCo3. So what I'm stuck on is this: Suppose the precipitate formed...

**algebra 2**

how to find the value of sec theta -15/4 and Tan theta 12 when theta is greater than zero and less than 360

**chemistry **

lactic acid is the avid responsible for the sour test in spit milk. on the basis of combustion analysis, it's percentage composition by mass is 40.00% carbon, 6.71%hydrogen and x% oxygen. a. Calculate the empirical formula of lactic acid b. The molar mass of lactic acid is...

**physics**

Thank you!!

**physics **

How long would it take a 750W electric motor to do 1.5x10^5 of work What I have so far: So we know w=fappxd 1.5x10^5=750xd So we can arrange that to find d. And then maybe use a formula to find t? Thank you!!

**Physics **

Determine the amount of work required for each of the following: a) to lower a 35kg sack of rice through a height of 3.5m b) to carry the 30kg sack of rice 10m along a corridor c)to crave the sack of rice 15m along the corridor at a constant velocity against a frictional force...

**Physics**

Sorry I meant to write 200g

**Physics**

A 200h bag of potato chips contains 4.8MJ of energy. How long would it take you working at your maximum body power to consume this energy? So we did 2 trials where we ran up the stairs, and my final power for 1 was 246W and for the other it was 338W. So I assume you divide the...

**Physics **

Hello so my question is an 85kg kangaroo acquires 2.2kJ of energy in jumping straight up and down from rest. How high does the kangaroo jump? My solution: When he's at rest Eg=2200J but in air Eg=0 Eg=mhh 2200=85(9.8)h 2.64m=h Looking at it now it doesn't really make ...

**math **

3 fourth of a class are boys. The girls are 24 less than the boys. How many pupils are in the class?

**Maths**

Karan took a loan of rs 70000 from a bank. If the rate of interest is 10%per annum find difference in amount he would be paying after 1.5 year if the interest is compound annually and compound half yearly

**Math**

Thank u

**Math**

IS this correct? 1.90+.80+.80+.80=$4.30

**Math**

Im not sure where to start

**Math **

A taxi service charges a $1.90 fee for each ride plus an additional .80 per mile. If a taxi ride cost $4.30, how many miles did the taxi travel travel during the ride?

**Math**

A rectangular garden has a length if 6.8 meters and seea perimeter of 20.6 meters. What is the width if the garden?

**Math**

Thanks Ms. Sue

**Math**

Lol... Sorry is this better? 3.75

**Math**

Is this correct? 49.8

**Math**

A carpenter cut pieces from a 12 foot long board that were 4 3/4 feet long and 3 1/2 feet long. What is the length of the remaining part if the board?

**Math**

Thank u

**Math**

Factor the following expression completely: 2ab+6a+12abc

**Math**

What does this mean >

**Math**

Ziggy earned $7.50 per hour plus an additional $100 in tips in Saturday. He earned more than $145 in all. Write an inequality to show h, the amount of hours he may have worked on Saturday.

**Math**

Thanks

**Math**

Yes mam, 2 1/4 and they are all teaspoons and the other is 1 1/8

**Math**

A recipe calls for 2 1/4 of salt for every 1 1/8 teaspoon of black pepper. How many teaspoons of salt are needed for each teaspoon of pepper used?

**Math**

Still don't understand

**Math**

Rita's baby brother weighed 7 5/16 pounds when he was born. Since then, her brother has gained 3 3/4 pounds. How much does Rita's baby brother weigh now? Express your answer as a fraction and as a decimal.

**Chemistry **

Write the equations for the reactions in which acids and bases are neutralized by the buffer consisting of HCOOH and HCOONa is a water solution in order to maintain a relatively constant pH of the solution?

**Math**

Thanks so much Ms.Sue

**Math**

If a person walks 4/5 miles in each 1/10 hr. How fast is the person walking per hour?

**Math**

Thank u

**Math**

If a women currently makes $20 per hour, but gets a 10% raise which represents 1/10 of her hourly wage, what will be her new hourly wage?

**Math**

Which way do I write it?

**Math**

350÷40=8.75

**Math**

Is this correct? 40* 8.75= $350

**Math**

Amanda uses the equation y=kx to determine how much money she earns after working any number of hours (x). Amanda earned $350 after working 40 hours. What is the value of k in Amanda's equation?

**Math**

Thank u Ms. Sue

**Math**

14=560÷40 Is this correct?

**Math**

The amount of money Jeff earns varies directly with the number if hours he works. Jeff worked 40 hours and earned $560. What is the constant of variation (in other words, what is Jeff's hourly wage) for Jeff's earnings?

**Math**

Tyrone's bank account had a balance of -$61.25 last week. His paycheck of $291.75 was deposited this week. What is his bank account balance now?

**PHYSICS**

An object acted on by three forces moves with constant velocity. One force acting on the object is in the positive x direction and has a magnitude of 6.2 N ; a second force has a magnitude of 5.0 N and points in the negative y direction Find the magnitude of the third force ...

**math**

dev has 120 stickers.he is going to get some more stickers,n,from his friend.write an expression using n to show how many stickers dev will have. please could you do it quickly i have to give this in after the half term and the other question i did!!!

**math**

the difference between two whole numbers is 15.one of the numbers is 1.there are two possibilities for the second number. what are they?

**Math**

30^2 =900 square inches

**Math**

How do i figure out if Ross doubles the length of each side of the picture? What is the are of the new square picture?

**Math**

Is rhe answer 225

**Math **

Ross uses nylon string as a border around a square picture. The string is 60 inches long. What is the area of the picture in square inches? Show your work.

**Math! Please help!**

This is an inequality problem/question. I dont know if I'm right in solving this problem: 15 ?-k/4-9 (k/4 is a fraction) Please help! I got 5.25 ?k

**Geometry **

in two congruent triangles the ratio of lengths of two corresponding sides is 5:8. If the perimeter of the larger triangle is 10 ft less than twice the perimeter of the smaller triangle find the perimeter of each triangle

**Physics**

Hello, I have a question and I would like to know if anyone can help me. Well I was reading about the motion of an ideal "yo-yo" and I found that mechanical energy is conserved, but there´s something that I don´t understand and it´s about the work ...

**Physics**

A wrecking ball is swinging at just the right height so that the student can stand at the bottom of the trajectory (lowest point) and grab onto the ball to swing – something that is just way too tempting for this inquisitive student. In order to justify invading the ...

**Math **

The sides of the rectangle are in the ratio of 4:7. If its length is 31.5 in., find the width, the perimeter, and the area of this rectangle.

**Math**

Would you please help me?? Anyone??

**Math**

The result of reflecting across the line y = x and then rotating 330 degrees counterclockwise around the origin is an isometry T . Represent T by a 2 ? 2 matrix. There is more than one way to do it. Use the point (1, 1) to check your answer. I know how to make the matrices but...

**Chemistry**

How many grams of urea would have to be dissolved in 250 grams of water to give it a freezing point of -4.degrees celcius

**MATH**

Is 1/5 a Irrational number Rational neither

**Math **

A marathon runner runs 10 1/2 miles in 2 hours. What is her rate? Write an expression to represent the problem. Solve the problem:

**Math**

Thank u

**Math **

On a soccer team 40% of the goals are scored by the star player. If 70 goals are scored all season, how many are scored by the rest of the team?

**Math **

Elizabeth pumps 3 1/2 gallons of gas in 1/4 of a tank. How many gallons does a full tank hold? Write an expression to represent the problem. Solve the problem:

**math**

If the half life is 24360 years and after 1000 years I have 2.1 gm left, what was the initial qty. Doing it in a common sense way keeps giving me 51gm and that doesn't make sense. formula is y=ae -bt

**Math**

An oil spill spreads 25 square meters every 1/6 of an hour. How much area does the oil spill in two hours?

**Math**

Sway has 3 red roses in her bouquet for every 5 yellow roses. The bouquet has two dozen red and yellow roses. How many are yellow roses?

**Math**

Sorry it's 5 minutes

**Math**

The average 3rd grade student can read 60 words I 5 minutes. What is the average reading per rate? Write an expressionto represent the problem. Solve the problem

**Math**

Thank u Ms.Sue

**Math**

Rate= 5.25

**Math**

A Marathon runner runs 10 1/2 miles in 2 hrs. What is her rate? Write an expression to represent the problem. Solve the problem.

**grammar**

Which sentence correctly uses a nominative case pronoun? A. Have her and Julie been to the downtown mall recently. B. Don and them are wonderful friends. C. The campers and we gathered around the bonfire. D. The only ones who received ribbons were Paul and me.

**Math 1**

In a study of 500 men, diastolic blood pressure was found to be approximately normally distributed, with a mean of 82 millimeters (mm) of mercury and standard deviation of 10 millimeters. Use the 68-95-99.7% rule to determine what percentage of the test group had a diastolic ...

**Government**

How do political cleavages shape people's opinions?

**Trig Question**

Find solutions of the following equation which lie in the interval [0,2pi): 6cos(3theta)/(2)+3=0

**algebra**

simplify. 6/ ?3 + 2 A.4/?3 B.12-6?3 C.?3 - 2*** D.3 ***my answer

**Math**

Fill in the blanks. 56 ÷ 7 = ____ ones ÷ 7 = ____ ones = ____

**Math**

21?

**Math**

A phone company uses the equation y=0.15x+10 to find y, the monthly charges for a customer sending x text messages. How many text messages are sent if the monthly charge is $77.50?

**ACCOUNTING**

On April 1, 10,000 shares of $5 par common stock were issued at $22, and on April 7, 5,000 shares of $50 par preferred stock were issued at $104. On April 20, 5,000 shares of common stock were issued in exchange for land. The stock had a market value of $23 on that date. ...

**Statistics**

Thirty-three small communities in Connecticut (population near 10,000 each) gave an average of x = 138.5 reported cases of larceny per year. Assume that ? is known to be 42.9 cases per year. (a) Find a 90% confidence interval for the population mean annual number of reported ...

**linear modles (math)**

multiply 2.61*4.5 and round to the tenths. There are 10 tenths in a n inch I believe. Sorry if I didn't help.

**Is My Answer Correct Tutors?**

You deposit $9,000 in an account earning 5.5% interest compounded semiannually. How much will you have in the account after 10 years? (Note: Use n=12 for monthly compounding, n=4 for quarterly compounding, n=2 for semiannual compounding, and n=1 for annual compounding.) $15483...

**algebra 1**

Harold's car has a fuel tank with 12 gallons of fuel in it. The fuel efficiency of Harold's car is 25 miles per gallon. Write an equation to represent the amount of fuel remaining, f, in Harold's car after driving m miles.

**Math**

In a circus a tightrope is stretched from the top of a 10 ft. pole to the top of a 25 ft pole. The poles are 36 feet apart and vertical. How long is the tightrope? Show your work.

**Math**

F(x)= 3/2x +b In the function above, b is a constant. If f(6)=7, what is the value of f(-2) ?

**Math**

If (t/5)/(t-5)=10 what is the value of t ?

**PreCalc**

2x^3+x^2-8x+3>0

**Statistics**

Please help I don't know how to solve this problem : Trevor is interested in purchasing the local hardware/sporting goods store in the small town of Dove Creek, Montana. After examining accounting records for the past several years, he found that the store has been ...

**Statistics**

What is the average miles per gallon (mpg) for all new cars? Using Consumer Reports, a random sample of 35 new cars gave an average of 21.1 mpg. (a) Identify the variable. new cars total miles all cars miles per gallon (b) Is the variable quantitative or qualitative? ...

**Statistics**

Thank you so much, I appreciate it!

**Statistics**

Please help, I do not understand how to do this: Let x be a random variable that represents white blood cell count per cubic milliliter of whole blood. Assume that x has a distribution that is approximately normal, with mean ? = 7400 and estimated standard deviation ? = 2900. ...

**Statistics**

Suppose the heights of 18-year-old men are approximately normally distributed, with mean 66 inches and standard deviation 4 inches. (a) What is the probability that an 18-year-old man selected at random is between 65 and 67 inches tall? (Round your answer to four decimal ...